<nz-col [nzSpan]="12">
  <nz-input-group nzPrefixIcon="anticon anticon-picture">
    <input nz-input name="captcha" [(ngModel)]="value" [placeholder]="placeholder" type="text" (click)="initImg()">
  </nz-input-group>
</nz-col>
<nz-col [nzSpan]="12" class="text-right">
  <img (click)="clearimg()" [src]="captchaUrl" *ngIf="captchaUrl">
</nz-col>
